怎么把前边的表查询成后边结果的格式的

[jtbreeze]

小弟初学sql，像高手求教,谢谢！
year month amount
1991 1 1.1
1991 2 1.2
1991 3 1.3
1991 4 1.4
1992 1 2.1
1992 2 2.2
1992 3 2.3
1992 4 2.4
结果
year m1 m2 m3 m4
1991 1.1 1.2 1.3 1.4
1992 2.1 2.2 2.3 2.4

[ktr__]

 
select year,
 max(case month when 1 then amount else 0 end) as m1,
 max(case month when 2 then amount else 0 end) as m2,
 max(case month when 3 then amount else 0 end) as m3,
 max(case month when 4 then amount else 0 end) as m4
 from t1
 group by year;

[ACMAIN_CHM]

http://blog.csdn.net/acmain_chm/article/details/4283943 MySQL交叉表 在某些数据库中有交叉表，但在MySQL中却没有这个功能，但网上看到有不少朋友想找出一个解决方法，特发贴集思广义。http://topic.csdn.net/u/20090530/23/0b782674-4b0b-4cf5-bc1a-e8914aaee5ab.html?96198现整理解法如下：数据样本： create table tx( id int primary key, c1 c...

[jtbreeze]

谢谢两位高手！